MAX17606 Secondary-Side Synchronous MOSFET Driver for Flyback Converters General Description Benefits and Features The MAX17606 is a secondary-side synchronous driver Wide 4.5V to 36V Input and controller specifically designed for the isolated flyback 2A/4A Peak Source/Sink Gate Drive Currents topology operating in Discontinuous Conduction Mode Suitable for Discontinuous Conduction Mode (DCM), (DCM) or Border Conduction Mode (BCM). By replacing Border Conduction Mode (BCM) the secondary diode with a MOSFET, the device improves 320A (typ) Low Quiescent Current the efficiency and simplifies thermal management. The Programmable Turn-Off Trip Point 7V V of the device makes it suitable for switching DRV Programmable Minimum Off-Time to Handle DCM both logic-level and standard MOSFETs used for flyback Ringing synchronous rectification. The 36V input voltage allows Thermal-Shutdown Protection it to drive from either the output voltage or rectified drain 6-Lead SOT-23 Package voltage of the secondary MOSFET. Programmable minimum on and off-times provide flexibility needed to handle Applications transformer parasitic element-related ringing in a robust High-Efficiency Isolated Flyback Converters manner. With 2A/4A source/sink currents, the MAX17606 is ideal for driving low R power MOSFETs with fast DS(on) Ordering Information appears at end of data sheet. gate transition times. Typical Application Circuit for 24V to 5V, 3A Isolated Flyback Converter V IN V OUT T1 5V,3A C1 C4 C9 4.7F 100F 1nF x4 C2 IN 6x R9 PGND 0.1F R5 D1 4.7 0 47 SS U1 C10 MAX17597 R1 R10 2.2F V IN 49.9k 2.74k 0 RT Q1 DRN N DRV T OFF R6 Q2 GATE R14 220 U2 V 100k IN CS C7 MAX17606 2.2F C5 R7 GND 1nF 0.02 EN/UVLO V DRV 0 0 DITHER V R11 OUT OVI U3 470 V 4 1 SGND DRV C6 C8 R12 EP 1.5k 2.2F 0.22F COMP FB 3 2 R4 R2 22k 49.9k U4 R13 C3 R3 R8 487 T1-WE750342955 22nF 10.5k 470k Q1-FDMS86102 LZ Q2-BSZ040N04LSG 0 19-7758 Rev 0 10/15MAX17606 Secondary-Side Synchronous MOSFET Driver for Flyback Converters Absolute Maximum Ratings V to GND ..........................................................-0.3V to +40V Continuous Power Dissipation (multilayer board) IN T to GND .........................................................-0.3V to +6V (T = +70C, derate 9.1mW/C above +70C.) ........727.3mW OFF A DRN (low impedance source) to GND .................-0.3V to +70V Operating Temperature Range ........................ -40C to +125C DRN to GND (up to 5mA of pull out current) .......... Self-Limiting Junction Temperature ................................................... +150C GATE to GND ..........................................-0.3V to VDRV + 0.3V Storage Temperature Range ........................... -40C to +150C V to GND ..............................-0.3V to Min (V + 0.3, 18)V Soldering Temperature (reflow) .................................... +260C DRV IN Continuous Power Dissipation (single-layer board) (T = +70C, derate 2.7mW/C above +70C.) ........219.1mW A (Note 1) Package Thermal Characteristics SOT-23 6L Junction-to-Ambient Thermal Resistance ( ) ........110C/W Junction-to-Case Thermal Resistance ( ) ...............50C/W JA JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Electrical Characteristics V = 12V, C = 100nF, C = 2.2F, GATE = OPEN, DRN = 0V, GND = 0V, R = 40.2k, T = T = -40C to +125C, unless IN VIN VDRV TOFF A J otherwise noted. Typical values are at T = +25C. All voltages are referenced to GND, unless otherwise noted. (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V IN V Operating Range V 4.5 36 V IN IN V Quiescent Current I DRN = 2V, no switching 320 450 A IN Q DRN switching -150mV to +2V, V Switching Current I 600 A IN SW 300kHz, 50% duty cycle V DRV V Regulation Voltage V 1mA V 20mA 6.6 7.0 7.4 V DRV DRV LOAD DRV V Regulation Voltage V I = 1mA 8.5V V 36V 6.6 7.0 7.4 V DRV DRV LINE VDRV IN V Dropout Voltage V I = 20mA ,V = 4.5V 4.1 4.3 V DRV DRV-DO VDRV IN V Current Limit I V = 6V V = 8.5V 26.5 55 mA DRV VDRV DRV IN V V rising 4.0 4.25 4.47 V V Undervoltage DRV-UVR DRV DRV Lockout V V falling 3.75 4 4.25 V DRV-UVH DRV DRN Maximum Drain Operating V 60 V DRN Voltage GATE Turn-On Detect V -150 -94 mV GATE-ON Threshold GATE Turn-Off Detect V 24 30 35 mV GATE-OFF Threshold DRN Rising Threshold for V DRN-TOFF DRN voltage rising 0.87 V T Enable OFF EN DRN Bias Current IDRN R = 40.2K, DRN = 0V 26.5 30.5 34.5 A TOFF Maxim Integrated 2 www.maximintegrated.com